Analysis of constituents of engine oil provides information on current conditions of the engine and may identify problems which may require costly repair if not corrected. Analytical services of this type have been provided through use of a kit type service in which a sample of the engine oil is mailed to an analysis laboratory and a report is furnished after the laboratory conducts an analysis using conventional analysis equipment such as a polychromator with rotatable carbon electrodes. Such technology involves a delay of several days. Improved maintenance of engines, vehicles and other equipment could be obtained by providing analytical equipment in the garage or other maintenance facility for use by a technician operating in a shop environment.